In many regions of the world, the water available for drinking and washing, or for various industrial purposes, has a high mineral content, which not only makes the water unpleasant to drink, but reduces its usefulness in washing, cooking, and industrial processes which require more pure water. This is particularly true of wellwater in rural areas. There are many different types of fresh water stills especially designed to purify water, often in the small quantities used in a domestic installation, but most of the stills available for this purpose are very difficult to clean. Particularly in areas where the mineral content in the wellwater is highest, small distillation units build up deposits of minerals causing caking in the apparatus at a high rate. Unless these deposits are removed periodically, they first reduce the efficiency of the still, and eventually render it entirely inoperative. The present disclosure provides a still having multiple different chambers connected in series with each other and including a boiling chamber, a steam separator chamber, and a condenser chamber.
U.S. Pat. No. 3,080,302 to Rogers et al shows a still having three chambers of this type connected in series with each other and comprising separate vessels. U.S. Pat. No. 1,466,535 to Kyrides and provides means for maintaining a desired liquid level within the steam separator. U.S. Pat. No. 3,138,546 to Muller also provides a liquid height tube arrangement for controlling the height of liquid in a separator unit which comprises a chamber separate from the boiling chamber of the unit.
U.S. Pat. Nos. 1,252,962 to Soderlund et al and 3,975,241 to Smith show float valve arrangements for maintaining a predetermined liquid height, the former patent showing it in a boiling chamber of a distillation unit. U.S. Pat. Nos. 3,838,016 to Powers, 3,935,077 to Dennison, 4,052,267 to McFee, and 3,350,279 to Tochin all showed distillation systems having a fan for forcing cooling air through a condensing chamber.
U.S. Pat. Nos. 4,139,418 to Sech and 4,052,267 to McFee both show sleeves extending upwardly around a heater unit which heats the liquid in a boiling chamber, these tubes assisting the convection pattern in the chamber to provide more rapid generation of steam.
The above features all bear similarity to features of the present still, but do not provide a still construction which is readily demountable for easy cleaning.